Artificial stone and process of making same.



"'cEoaeuA. 'PARSoNS, or WILMINGTON, MASSACHUSETTS, ASSIGNOR or cHUSETTS. p

' To all whom it may concern.-

- Be it known that I, GEORGE A. PARSONS, of Wilmington, in the county of Middlesex and State of Massachusetts, have invented cer- 5 tain new and useful Improvements in Artificial Stone and Processes of Making the Same, of which the following is a specification.

This invention has relation to the manufacture of artificial stone which may be molded into shape for employment in place of tiles,

bricks, &c.

The object of the invention is to provide, first, artificial stone in which the waste product forms substantially the entire base and 715 a process by means of which the artificial T stone may be produced most economically.

In the manufacture of the composition I employ as a base desiccated waste material, such as sawdust, and I prefer to employ the' last-named substance because it has not only heretofore been allowed to go to waste, but it is sufficiently comminuted to serve my pur- 'j poses, being porous and adapted to receive *the solution, which renders it hard and durable.

In carrying out my process I first subject the'sawdust to a desiccatin process to re move a molstumch it is mixed with silic to of sodain solution. To produce this siolufiionfi employ silica SiOfl in powp Qeyv form and mix it wi t ree or more times its welg t of c' (NaOH) and after *etin eat our the mixture "7111 5.1 en add, in the pro- '35 portion of one to ten, ak acid to renj der the solution I t atin th empfo ye for this purpose. e sawdust is mixed with the solution, suflicient of the so- 1 4o lntion being employed t0 thoroughly perme-.

' ate the pores of the sawdust and make a plastic mass. The mass is dried until it becomes -ratedWithasoluowe ry suilclen y enableitto' be jis-madeflin'to.any form desire he comv ny miner d may behandle d, when it is subjected to pressujend i 'pressed masses are then exposed to air 'nd FOUR-FIFTHS TO JAMES W. SMITH AND JAMES P. PHELAN, OF LYNN, CHARLES ILSMITH, OF DORCHESTER, BOSTON, HERBERT H. PRATT, OF SWAMPSCOTT, AND HORACE M. BRIGGS, OF EAST FOXBORO, MASSA- ARTIFICIAL'STONE AND PRocEssoF MAKING SAME.

SPECIFICATION forming part of Letters Patent No. 668,413, dated February 19, 1901. Application filed April 13,1900. Serial to. 12.789. (No specimens.)

are allowed to harden. The resultant com- 4 tion is variously colored, whereby it may be used in mosaic-work.

The pigments are added during any of the e I steps of the process in forming the composition.

In lieu of sawdust I may employ any other it vegetable substance in a comminuted state; 1

It is evident that in lieu of sodium hydrate or caustic soda I may employ the hydrate of "6 5 any other alkali metal, although I prefer to use caustic soda rather than caustic otash, I as the latter isdeliquescent and the io'r'm' r is efiiorescent.

Having thus explained my invention,-'what I claim is V 1. An artificial-stone composition consisting of a vegetable base, a compound of silica and hydrate of an alkali metal the latterpredominating over the silica in the proportion of three or more of said hydrate to one of the silica, a weak acid, and lime.

2. The herein-described process which consists in mixing silica in powdery form with three or more times its weight of a hydrate of an alkali metal and heating them to white heat and then pouring the mixture into boiltion, adding a'weak acid to neutralize the soda and strengthen the adhesive quality of the mixture, impregnating desiccated vegetable matter-with the solution thus formed, partially drying the mass and then treating it with a solution of lime, then drying and pressing the composition and finally exposing the compressed mass or masses to air to GEORGE A. ,rninsons.

ing water to produce silicate of soda in solu- 1' 

